International Patent Application No. PCT/NL2007/050665 discloses an innovative assembly comprising a fluid channel and a flowmeter, and a method to measure a fluid flow rate. The known flowmeter comprises a vortex shedder extending in the channel, the vortex shedder being configured to generate Karman vortices in fluid flowing through the channel during operation. The vortex shedder is provided with a fiber Bragg grating (FBG) of a fiber Bragg grating sensor. During operation, a Karman vortex frequency of the vortices generated by the vortex shedder is detectable utilizing a fiber Bragg grating sensor signal relating to the respective fiber Bragg grating of that vortex shedder. In a further advantageous embodiment, the known flowmeter is configured to detect a temperature, particularly using a fiber Bragg grating, as well.